Oral myofibroma is a rare tumour which usually occurs in children and has been reported in the mandible, tongue, buccal mucosa with only a few cases reported from the gingiva. It appears alarming clinically due to its fast growth which may mimic a malignancy. However, it is completely benign and is usually treated by complete surgical excision with excellent prognosis. Clinically, myofibroma presents as a single swelling when it occurs on the gingiva, and more common lesions such as fibrous epulis, pyogenic granuloma and peripheral odontogenic fibroma, myofibroma are usually considered in the differential diagnosis. We present 4 additional cases of gingival myofibroma in children. Their ages ranged from 7 to 14 years. Three were girls and 1 patient was a boy. All presented with solitary gingival growths, ranging from 3 weeks to 2 months in duration, and raised the clinical diagnoses of peripheral giant cell granuloma, pyogenic granuloma and fibrous epulis. Histopathology of incisional biopsies revealed proliferation of streaming and whorled fascicles of spindle cells around slit-like vascular spaces. The spindle cells were cytologically bland and were immunopositive for vimentin and smooth muscle actin, but were negative for desmin and S-100 protein. All were treated by surgical excision.
Child ; seconds ; Granuloma ; spindle cell ; findings

Rosai-Dorfman disease (RDD) is a rare benign proliferative disorder of histiocytes in the lymph nodes with or without extranodal involvement. RDD limited to the skin without nodal involvement, known as cutaneous Rosai-Dorfman disease, is very rare. We describe a 34-year-old female with RDD of the skin over the chest. A large nodule with satellite lesions was excised for histopathological examination. Microscopically, there were many large histiocytes (Rosai-Dorfman cells) exhibiting emperipolesis, among many plasma cells, lymphocytes and neutrophils throughout the dermis and the subcutaneous tissue. The histiocytes were immunohistochemically positive for S-100 protein but negative for CD 1a. Physical examination showed no lymphadenopathy or any extra-cutaneous lesions. Serological tests indicated a past infection with Epstein-Barr virus and cytomegalovirus. The diagnosis of cutaneous RDD may be difficult in the absence of associated lymphadenopathy or any specific features of the skin lesion. Hence, not only is histopathological examination required for definitive diagnosis but a high index of suspicion by the clinicians and pathologists is essential to help diagnose this very rare disease.
seconds ; Cutaneous ; Histiocytes ; Enlargement of lymph nodes ; Diagnostic

This was a retrospective study of dentigerous cysts in people from the Singapore-Malaysian region. The purpose of this study was to present the clinicopathologic features of dentigerous cysts in the Oriental population and to compare these data with those from other reported studies. Biopsy records from 1981 to 1993 of 119 cases of dentigerous cysts from patients in Malaysia and Singapore showed that 36.1% of patients were female and 63.9% patients were male. Among patients with cysts, 70.5% were Chinese, 23.2% were Malays, 2.7% were Indian and 3.6% were other ethnic groups. The mean age of these patients was 30.2 +/- 17.3 years with a peak incidence occurring in the second and third decades. The location of the lesions was almost equal to the maxilla (50.9%) and the mandible (49.1%). There was a marked predilection for the posterior mandible (42.7%) followed by the anterior maxilla (38.2%). Histologically, 90.8% of the cysts were lined by a non-keratinised stratified squamous epithelium. The cyst linings were mainly thin (90.0%) with 38.7% of cases having a mixed thick and thin lining. Mucous metaplasia was observed in 9 (7.6%) cases. Rushton bodies were seen in 3.4% of cases. Cholesterol clefts in the epithelial lining and lumen were found in 16.8% cases while 12.6% of cases exhibited cholesterol clefts in the cyst wall. Other cellular structures within the cyst wall were lymphocytes (66.4%), plasma cells (52.1%), Russell bodies (16.0%) and histiocytes (4.2%). Odontogenic keratocysts were observed in 5.0% of cases. One case of adenomatoid odontogenic tumour was also observed. Epithelial atypia was seen in 9.2% of cases, islands of stratified squamous epithelial cells in 8.4% of cases while one case showed a combination of these two features. In conclusion, some clinical features seen in this study are similar to that for the Caucasian population such as prevalence in male, peak incidence in the second and third decades and the predilection for the posterior mandible and anterior maxilla. Histopathologically, odontogenic keratocyst and adenomatoid odontogenic tumour were observed in dentigerous cysts.
seconds ; Singapore ; Maxilla ; Mandible ; Malaysia

Hepatocellular carcinoma (HCC) ranks as the fifth most common cancer with an increasing frequency worldwide. "Nuclear atypia", one of the critical features in histological diagnosis of malignancy and grading of the tumour, is generally ascertained through eyeballing. A study was conducted at the Department of Pathology, University of Malaya Medical Centre to assess whether nuclear area, (surrogate measure for nuclear size) and standard deviation (surrogate measure for nuclear pleomorphism) when objectively measured via computer-linked image analysis differs between (1) benign and malignant liver cells and (2) different grades of HCC. A 4-microm thick H&E stained section of 52 histologically re-confirmed HCC with 36 having benign, non-dysplastic surrounding liver were analysed using the Leica Q550 CW system. 10 consecutive non-overlapping, non-mitotic and non-apoptotic nuclei of HCC and surrounding benign hepatocytes respectively were manually traced at 400x magnification on the computer monitor and the nuclear area for the particular cell computed in arbitrary units by the Leica QWIN software. A total of 360 benign hepatocytic nuclei, 240 low grade HCC and 280 high grade HCC nuclei were traced. The mean nuclear area of the benign hepatocytes (37.3) was significantly smaller (p < 0.05) than that of both low grade (65.2) and high grade HCC (80.0). In addition, the mean nuclear area of high grade HCC was significantly larger (p < 0.05) than the low grade HCC. SD of the nuclear areas was lowest in benign hepatocytes (9.3), intermediate in low grade HCC (25.0) and highest in high grade HCC (25.6). These findings indicate that computer-linked nuclear measurement may be a useful adjunct in differentiating benign from malignant hepatocytes, in particular in small biopsies of well-differentiated tumours, and in predicting survival after surgical resection and transplant.
Grade ; Benign ; Computers ; Malignant Neoplasms ; Cancer cells grading system

The unique ability of tumour cells to proliferate indefinitely is crucial to neoplastic progression as it allows these cells to express the aggressive properties of cancer without the censure of physiological ageing. This is in contrast to normal somatic cells which are subject to a "mitotic clock," a phenomenon that has been linked to telomeric shortening after each round of cell replication, so that eventually the loss of genetic material reaches a critical stage and the cells undergo senescence and cell death. A study was conducted to investigate the role of telomerase, an RNA-containing enzyme that restores the telomere length, in the neoplastic cell immortalization and progression process. Fresh human tissue samples taken from excision specimens received by the Department of Pathology, University of Malaya Medical Centre, were investigated for telomerase activity using a commercial Telomerase PCR-ELISA kit (Boehringer Mannheim). Specimens comprised 33 breast lesions (10 infiltrating breast adenocarcinoma, 13 fibroadenoma and 10 non-neoplastic breast tissue), 27 colonic lesions (17 colonic adenocarcinoma and 10 non-neoplastic colonic mucosa) and 42 cervical lesions (20 cervical carcinoma and 22 non-neoplastic cervical tissues). Telomerase activity was found in 6 (60%) of 10 breast carcinomas, 6 (46%) of 13 fibroadenomas, none of the 10 nonneoplastic breast samples, 3 (17.6%) of 17 colon carcinomas and none of the 10 non-neoplastic colonic mucosal samples, 12 (60%) of 20 cervical carcinoma and 3 (13.6%) of 22 non-neoplastic cervical samples. 5/10 (50%) Stage I, 4/7 (57%) Stage II, 2/2 (100%) Stage III and 1/1 (100%) Stage IV cervical carcinomas showed telomerase activity. These findings support a contributory role for telomerase in tumourigenesis with activation occurring from neoplastic transformation and increasing with tumour progression.
Telomerase ; seconds ; Breast ; neoplastic cell ; Progression

Two duplex PCR assays were established for the detection of C. trachomatis (Ct), N. gonorrhoeae (GC), M. hominis (Mh), and U. urealyticum (Uu). These assays were used on clinical specimens obtained from women with Premature Rupture of Membrane or Post Partum Fever, from preterm infants, as well as from women with uneventful pregnancies and their babies delivered vaginally at term. The analytical sensitivity of the duplex PCR assays with internal controls incorporated is 7.0, 19.0, 5x10(3) and 7x10(2) genome copies per reaction for Ct, GC, Mh and Uu respectively. Specificity was demonstrated by the amplification of only target DNA in the presence of other organisms. Among 40 women with normal, at term, deliveries, there were 6 positives for Ct, 2 for GC and 1 for Uu. None of these women had signs of genital tract infection. The Mh/Uu PCR was positive in 11 of 40 PROM cases, with 7 women positive for Uu, 2 for Mh and 2 others for both organisms. Of 40 blood cultures taken from post-partum maternal infections, 6 were positive for Ct and 1 for Mh. Respiratory secretions from 30 premature neonates yielded 5 positives for Uu and one each for Mh and Ct. In contrast, there was only 1 positive result (for Mh) in 30 mature neonates. With 1 exception, all mycoplasma and ureaplasma positives were confirmed by culture and the concordance between paired tracheal aspirates and nasopharyngeal swabs from neonates was 96.7%. These results show the potential use of the duplex PCR assays for the diagnosis of maternal and neonatal disease caused by the four urogenital pathogens.
Polymerase Chain Reaction ; Human Females ; seconds ; Neisseria gonorrhoeae ; Infant, Newborn

The challenges to the teaching of undergraduate pathology include adapting to the ever-evolving medical curriculum and the emergence of new teaching technologies. Nevertheless, pathology remains the crucial bridging medical discipline, with the pathology teacher playing an important role in consolidating the basic medical sciences and leading in the clinical disciplines. In this report, variations of case-based teaching of undergraduate pathology are discussed. These can be used in pathology lectures, tutorials and practical sessions, both traditional and computer-based. They contribute to the pathology teacher's repertoire of teaching tools and help add relevance and zest during class.
Pathology processes ; Teaching aspects ; TEACHERS ; Methodology ; seconds

A mycological medium was developed for primary isolation and culture of lipophilic yeasts. It was initially based on published information of nutrients and trace components that would promote the growth of these yeasts. It was subsequently modified and adjusted to specifically promote the growth of lipophilic yeasts and simultaneously avoid the luxurious growth of other fungi and bacteria. With this medium, the conventional bacteriological procedures such as microbial streaking for pure culture and anti-microbial sensitivity testing could be carried out for these lipophilic yeasts.
Cultural ; isolation aspects ; growth aspects ; microbial ; Malassezia furfur

A simple and sensitive double-antibody radioimmunoassay for human growth hormone (HGH) was developed, optimised and validated. The anti-hGH sera raised in 2 rabbits were highly specific with low cross-reactions of 0.19% and 0.3% with human placental lactogen and 0.21% and 0.13% with human prolactin. The mean sensitivity of the assay determined from 28 assays was found to be 0.4 +/- 0.2 mIU/L. Mean recovery of added exogenous hGH was 98.8 +/- 6.8%. Linearity studies of samples diluted at 1:2, 1:4 and 1:8 gave values of 101.3 +/- 5.3%, 109.6 +/- 13.4% and 97.3 +/- 13% respectively of those expected. The reproducibility of the assay was good; within assay coefficient of variation for serum samples with GH concentrations of 2.7, 13.6 and 28.2 mU/l ranged from 5.1 to 8.3% while the inter-assay precision varied from 4.9 to 10.3%. The in-house assay showed good correlation (r = 0.96, p less than 0.001) with a commercial HGH RIA kit (Dainabot, Japan). A reference normal adult fasting GH level of less than 7 mIU/l was established from 95 samples assayed by this method.
Somatropin ; assay ; Radioimmunoassay ; L ; Growth hormone measurement

Most previous studies on RET and p53 proteins have focused on thyroid papillary carcinoma. We investigated the role of RET and p53 protein expressions using immunohistochemistry on 52 cases of thyroid follicular adenomas and studied the follow-up records of these patients. The range of follow-up period was 3 to 14 years. The patients were between 15 and 71 years of age with a median age of 34.5 years. There were 46 females and 6 males. Except for 3 cases, all patients were Malays. The minimum volume of the tumour was 1000 mm3 and the maximum was 512,000 mm3 with a median of 270,000 mm3. Eleven (21.2%) cases showed RET expression. RET expression was not statistically significant when cross-tabulated against sex (p = 0.322), ethnicity (p = 0.518), age (p = 0.466) and symptom duration (p = 0.144). Six (11.5%) of 52 cases showed p53 immunopositivity. p53 expressions were also not significantly correlated to the clinical parameters above. There was no correlation between RET and p53 protein expressions. The only statistically significant finding was the association of tumour volume with duration of symptoms (p = 0.05). All patients are alive at the time of writing. 3 had recurrent goitre, 2 of these were diagnosed as colloid goitre while the third was a follicular lesion. One patient suffered from depression requiring anti-depressant treatment. In conclusion, unlike papillary carcinoma in which the roles of ret and p53 oncogenes are known, their roles in influencing the behaviour of follicular adenoma has not been ascertained.
Oncogene, RET ; lower case pea ; Desiccated thyroid ; Protein p53 ; Age, NOS